1. Field of the Invention
The present invention relates to an organic light emitting device comprising an auxiliary wiring between pixels, a manufacturing method thereof, and a display unit using it.
2. Description of the Related Art
In these years, as one of flat panel displays, an organic light emitting display which uses organic light emitting devices has been noted. The organic light emitting display has characteristics that its visual field angle is wide and its power consumption is low since it is a self-luminous type display. The organic light emitting display is also thought of as a display having sufficient response to high-definition high-speed video signals, and is under development toward the practical use.
As an organic light emitting device, for example, as shown in FIG. 1, an organic light emitting device, wherein a first electrode 111, an organic layer 112 including a light emitting layer, and a second electrode 113 are sequentially layered on a substrate 110 is known. In some cases, the second electrode 113 is electrically connected to an auxiliary wiring 113A having a low resistance, in order to prevent variation of luminance in a screen by inhibiting voltage drop (for example, refer to Japanese Unexamined Patent Application Publication No. 2001-195008).
Regarding materials for the organic layer 112, there are two kinds of the organic layer 112: one is made of a low molecular material; and the other is made of a high molecular material. As a method of forming the organic layer 112 made of the low molecular material, vacuum deposition method is generally used. When the organic layer 112 is formed by the vacuum deposition method, as shown in FIG. 2, the auxiliary wiring 113A is prevented from being covered with the organic layer 112 by using a mask for pixel coating 120 having apertures 121 corresponding to a position where the organic layer 112 is to be formed. After that, the second electrode 113 is formed on almost a whole surface of the substrate 110, and thereby, the auxiliary wiring 113A and the second electrode 113 are electrically connected.
However, when a high-definition organic light emitting display is fabricated, it is hard to form the organic layer 112 precisely due to influence of thermal expansion of the mask for pixel coating 120. Further, when particles adhering to the mask for pixel coating 120 adheres to the organic layer 112 and the like, short circuit may arise. Therefore, it is desirable to form the organic layer 112 without using the mask for pixel coating 120. In this case, however, the organic layer 112 is formed on almost a whole surface of the substrate 110. This leads to a problem that the auxiliary wiring 113A and the second electrode 113 cannot be electrically connected.